Abstract: The invention is a resonant circuit sensor of physical properties of objects that monitors measurable properties of resonant circuits affected by interactions of the objects with the polarized, resonant oscillations of the circuits. The circuits can be passive with excitation by an external energy source or active with a source included as an integral part. Simultaneous or sequential sensing of more than one physical property of objects is obtained by detecting resonant oscillation characteristics such as amplitude, frequency, phase or polarization and by detecting quantities influenced by such characteristics for one or more orientations of the objects relative to the polarization of the oscillations. These resonant oscillations can be in the form of electromagnetic fields, electric fields, magnetic fields, or acoustic waves.